1. Technical Field
The present invention relates generally to wireless device networking and, in particular, to a method for call admission control in a wireless network.
2. Background of the Related Art
Wireless local area network (WLAN) technologies and services are well-known. WLAN is based on IEEE 802.11 standards. The Enhanced Distributed Channel Access (EDCA) defined in IEEE 802.11e allows multiple admission classes or classes of service (voice, video, best effort and, background) to be used to reflect the jitter and latency requirements of a specific application or service. While EDCA ensures a Quality of Service (QoS) marking of each 802.11 data frame, it is not sufficient to guarantee the required quality of service for an entire user session when the Wi-Fi user device moves among the access points (APs) comprising the Wi-Fi infrastructure.
The IEEE 802.11e standard also provides for Call Admission Control (CAC). The basic formula for the CAC function is based on the calculation of the airtime needed by a new user flow. In particular, if time occupied by the new flow is smaller than a surplus time, then communication with that priority is considered to be possible and the communication is approved. Otherwise, the communication is rejected. Thus, the main purpose of the CAC function is to determine whether there are adequate resources to provide the required quality for the service requested by a Wi-Fi user device.